DFM Overview & Injection Molding - MIT - October 7, 2014

DRAGON INNOVATION, INC. !

MIT EC.729 !

DFM OVERVIEW + INJECTION MOLDING !

OCT 7, 2014 !!!!!!!

SCOTT N. MILLER | CEO | @DRAGONINNOVATE | WWW.DRAGONINNOVATION.COM

mailto:[email protected]

Presentation Download

http://bit.ly/DFM-Injection-Molding-Overview

http://bit.ly/DFM-Injection-Molding-Overview

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Agenda

http://en.wikipedia.org

•Survey

•Dragon Background

•How to Select a Factory (RFQ)

•How to Work with a Factory

•Injection Molding Basics

http://en.wikipedia.org/wiki/M4_Sherman

Quick Survey

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DRAGON BACKGROUND

MIT RoboTuna

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Disney Dino

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My Real Baby

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Agenda

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DRAGON INNOVATION HAS HELPED LAUNCH AND SCALE OVER 100 COMPANIES SINCE 2009

HOW TO PICK A FACTORY !

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!*THE MOST IMPORTANT MANUFACTURING DECISION YOU’LL MAKE

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Overview of the CM Selection Process


1. Talk with trusted network connections who have manufacturing experience.

2. Create a differentiated list of 5 - 10 CMs.

3. Down select to 3 - 5 factories based on your product category (why?)

4. Create a Request for Quote (RFQ) Package.

5. Visit!

6. Analyze Results.

7. Negotiate Big Items.

8. Talk with the CM’s customers.

9. Select the winner, and leave the others on good terms.


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RFQ Package


•Company Overview -Team overview -Funding -Product -What’s done -What needs to be done -Factory Criteria

•BOM -Canonical format (A2A) in Excel -Transparent and Formula Driven -Separate Std, Special and Consigned Margins/Markups -Include all costs to Ex-Factory -Fill in the blanks

•Schedule -Gantt chart (Cloud) -Fill in the blanks


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Factory Visit Checklist


Do you like the team? Are they experienced and friendly?

Do they have the right manufacturing capabilities?

Does your intended volume match their volume capabilities?

Are they financially stable?

Do they have enough working capital to get going?

Do they have favorable payment terms?

Are they transparent in their costing?

Do they take IP seriously? Did they show you something they shouldn’t have?

Are they ethical in their treatment of their workers and otherwise?

Do you have access to upper management?

Are they excited about working on your product?


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CM Comparison (A2A Decision Matrix)


•Total Material Costs

•Labor

•Margins/Markup (Std, Special, Consigned)

•Pareto of Top 5 Most Expensive Components

•Fixed Costs (tooling, fixtures, NRE)

•Schedule

•Fit Criteria


HOW TO WORK WITH A FACTORY

POP QUIZ

• Question: What is the biggest challenge in manufacturing ?

Hint

POP QUIZ

• Question: What is the biggest challenge in manufacturing?

• Answer: Communication! • You cannot design in a vacuum (even if you design

vacuums). Strong communication and teamwork skills are critical to success. Engineering is team sport. It’s all about the people. “Us” and “Them” won’t work.

Communication At Work

Bi-Directional Knowledge Flow

Product Designed In U.S.A. Database Sent To Cm Tooling Manufactured

Parts Molded Product Assembled Final Inspection & Shipping

Manufacturing Management Triangle

Quality

Cost

Schedule

Cost of Goods Sold

(COGS)

• Direct costs for goods produced. • Does NOT include Tooling. • Actual price depends on where a

company takes ownership: - Ex-Factory (XF) - FOB (add overland transport to

XF) - Landed (add shipping to FOB) - Inventory (add warehousing)

• Price will vary by date depending on running changes, transportation costs, currency exchange, commodity costs, etc.

Very Simple Retail Costing Model

$

Sell-Through Price (Retail Price)

Sell-In Price (Wholesale Price)

COGS

Retailer Gross Profit

Company Gross Profit

COGS

COGS YOUR DESIGN

• Material and Component Selection

• Fabrication Method • Manufacturing Efficiency

(First Time Yield, machine tonnage, assembly labor, number of operations, etc.)

• Quality Requirements (driven by requirements / Voice of Customer)

• Packout (replaceable vs. rechargeable batteries; packaging; spares, etc.)

MANUFACTURING PARTNER • BOM Transparency • Profit Margin • Labor Rate • Currency • Geographic Location

(shipping, tariffs, etc.) • Capability (in-house vs.

outsourced) • Supply Chain (Purchasing

Power, volume (piggy back), Consigned vs Purchased, etc).

Controlling Costs

1.Deconstruct the BOM. 2.Separate special components. 3.Transparency 4.Compare to standards. 5.NegoEate Inclusions

Additional COGS Strategies

Cost

•Bill of Material Transparency: Require factories to provide an item by item costed BOM. No mysteries or hidden formulas.

•Calculate labor rates. Pop Quiz – How???

•Build a “Standard Cost” database. Price out cost reducJons.

•If Jme permits, develop relaJonships with mulJple vendors to avoid single source suppliers. Leverage is a beauJful word.

•When manufacturing in volume for a CE product, it is criJcal to understand and control COGS. Focus here! Because of the volume, every penny counts ($10k @ 1M units)

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ITEM NO. PART NUMBER DESCRIPTION QTY.

1 100132 Heatsink, Aavid 60520 12 PCB 1

100104 Circuit board blank 1 100015 LED, Luxeon LXHL-LW6C 1

3 GATE 1 100110 Film Gate 1 100011 Backgate 1 100024 Film Spacer 1

4 Bottom 1 100144 Bottom Plate 1 100029 Leaf Spring 2

5 Knobreel 2 100106 Cover Bush 1 100151 Dowel .125 dia 2.000 long 1 100009 Driver 1 100153 Gripring .125 dia 1 100149 Knob bush 1 100007 Clutch, one-way, Torrington RC-02 1 100152 Washer, ss .125 id, McMaster 98019A310 1 100017 Knob, plastic McMaster 7354K15 1 100045 Felt washer 1

6 Reel 27 condentube 1

100031 Condenser lens, small Fisher Price 1 100105 Condenser Tube 1 100154 O-ring Buna -120 1 100035 Retaining ring, internal 1.062 dia 1 100031b Condenser lens, large, Fisher-Price 2

8 100162 Spacer, condenser lens, short 19 100136 Spacer, condenser lens, long 1

10 100163 Spacer, projector, short 111 FHMS Phillips M4x20 812 PHMS Phillips M4x8 613 PHMS Phillips M4x6 514 PHMS Phillips M5x16 815 FHMS Phillips M4x12 616 PHMS Phillips M4x12 117 PHMS M4x8 618 100150 Endplate, Right 119 100160 Endplate, Left 120 100100 Front Plate 121 100138 Projector Lens Housing 122 100148 End Spacer 223 100145 Top Plate 124 100158 Window Edmund R39-773 125 100146 Handle 126 100161 M5 Acorn Nut 127 100147 Half Bridge 128 100012 Focus Screw McMaster 92558A170 129 100143 Spacer, .25 dia, .19 long 430 100156 Spacer, projector, long 131 FHMS Phillips M4x8 232 100150 Washer, Nylon, MSC 05401757 133 100159 Detent 134 100101 Bumper, rubber McMaster 9540K35 835 100039 Switch, SPST rocker Carlingswitch 136 100155 Projector lens, concave 137 100157 Projector lens, plano 1

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APPLICATION

DIMENSIONS ARE IN MILLIMETERSTOLERANCES: 0,1MM ANGULAR: 0 30'

MATERIAL

FINISH

DRAWN

APPROVED

DATENAME

TITLE:

SIZE

BDWG. NO. REV

SCALE 2:5

UNLESS OTHERWISE SPECIFIED:

KINKAJOU DELTA100141

DO NOT SCALE DRAWING

REMOVE ALL BURRS AND SHARP EDGES

allen 21july04

Anatomy of a BOM• Plastic • Purchased Parts • Electrical Components • Consigned Components • Deco • Packaging • Assembly Labor • CM Profit, Overhead and Scrap • Overland Transportation

• Does it matter that it is a gear???

• Components (3) 1.Material Cost = Part Weight * Resin Cost 2.Machine Overhead: = Hourly Cost * Cycle Time (sec) / (3,600 sec / hr) 3.Factory Mark-up, Scrap and Overhead (%)

• Total Part Cost: = (Material Cost + Overhead Cost) * (1+Factory M/U)

How to Calculate Plastic

HK Resin Prices (USD/Ton)

Reference: http://www.nhh.com.hk/eng/trading/price_trend.asp (you will need to create a login)

http://www.nhh.com.hk/eng/trading/price_trend.asp

Item Cost (USD)

280 Ton / hr $15.48

220 Ton / hr $10.96

180 Ton / hr $8.38

140 Ton / hr $7.09

100 Ton / hr $5.80

80 Ton / hr $5.16

Example PRC

How to Calculate EE Costs

• Cost = Component * Usage • Separate high cost components over a certain

threshold. Apply a lower mark-up. • Apply Factory M/U

Typical PRC CM Margins (Profit, Scrap, Overhead)

PCBA 6–8%

Toys 12%

Consumer 15%

Medical >40%

Other BOM Costs

• Deco (Tampo, Paint, etc.) • Labor (PRC $2 – 6 / hr) • Packaging (Gift + Master)

Add It Up

• Plastic • Purchased Parts • Electrical Components • Consigned Components • Deco • Packaging • Assembly Labor • CM Profit, Overhead and Scrap • Overland Transportation

Schedule

Schedule

•Many consumer products are driven by the Christmas (which has a fixed date). Plan conJngency in your schedule. Things never go according to plan.

Have an onsite presence. Track schedule carefully and take correcJve acJons early. Avoid: “There is never Jme to do it right the first Jme, but there is always Jme to do it again. ”

The Road to Production

Detailed Milestones‣Hand Over / Kick-‐Off

Form CM Team Contact Lists / Roles and ResponsibiliJes

ME and EE File transfer Works Like / Looks Like Samples CM trip to the US if possible (access to models and team, relaJonship building).

Factory Input Components

Engineering Quality ProducJon Planning (interface with Sales)

Sourcing / MA / CosJng LogisJcs Process / Procedure Financial (modeling and payments)

Pre-‐ProducJon Milestones Tool Release

Tool Start (TS) First Shots (FS) Engineering Pilot 1 (EP1) EP2 EP3 Final Engineering Pilot (FEP) ProducJon Pilot (PP)

ProducJon ProducJon Start (PS) Ramp

Engineering Change NoJce (ECN) Sustaining (Quality Up / Cost Down) Sunset

Quality

Quality•DefiniJons:

•Quality = Customer SaJsfacJon = Performance – ExpectaJons •“Fitness for Use” Incoming Quality Control: Use good ingredients. Build and test along the way. Use sub-‐components. StaJsJcal Process Control (SPC) / Yield. Find out now, not later. Sample TesJng: Temp/Humidity; TransportaJon; Drop; T/T; Small Parts; Heavy Metals;

Compliance; FuncJonal; Life. How do tests match reality? ISTA-‐3A. Final InspecJon / Acceptable Quality Levels (AQL) Walk the line. Get your hands dirty. It is much easier (and less expensive) to make changes before ProducJon Start. What happens if something fails? Will make or break a product … and a Company! Quality is rarely considered in the engineering phase by startups due to schedule, cost and

technical pressures. Watch out for the Unknown Unknowns. Strong indicator of long term success, etc. Can you answer the quesEon “How do you know the product is good”?

INJECTION MOLDING

•Overview •Molding Process •Part Design •Materials •Techniques •Shot Nomenclature •Tooling Fabrication

INJECTION MOLDING

Overview

Recommended References

www.matweb.com

http://www.amazon.com/Manufacture-Manufacturing-Engineering-Materials-Processing/dp/1420089277

http://www.amazon.com/Plastic-Part-Design-Injection-Molding/dp/1569904367

http://www.matweb.com

http://www.matweb.com

Typical Engineering Molded Parts (Examples)

• Housings / Brackets

• Transmissions

• Joints

Injection Molding Advantages

• Supports highly integrated design - Complex geometry and fine details possible

• Low part cost • High volume production • Wide range of thermoplastic materials and fillers • Wide range of sizes • Low scrap rate • High reproducibility & Reasonable tolerances • Little post production required • Good surface finish • Can be fully automated • Reduces piece count • Simplifies assembly

Injection Molding Disadvantages

• High tooling costs and long lead-times

• Difficult to make changes

• Large undercuts are difficult

• Requires nearly uniform wall thickness

• Limited to Thermoplastic materials

• Cannot produce very large parts as a single piece.

Molding Process

Molding Cycle

1. Melt Shot

2. Clamp and Fill

3. Pack (Gate Freeze)

4. Cool

5. Eject

Molding Process

Three Plate Mold

Part Design

Temp and Pressure

12k psi @ 440F

Shrinkage

Design Guidelines

• Design for 2mm uniform wall thickness (0.5mm – 6mm).

• Ribs 80% wall thickness. • Draft depends on texture and resin. Assume 0.5 deg. • Use rounds and fillets. No sharp edges except parting

line. • Shoot for planar parting line if possible. • Tolerance is a function of the resin, part geometry and

mold construction. • ABS: +/- 0.1mm • ABS Hole: +/- 0.05mm up to 6mm diameter.

• Surface Finish: SPI A-1 Grade 3: 6000 Grit Diamond

Reference: Product Design for Manufacture and Assembly. Geoffrey Boothroyd,, Peter Dewhurst and Winston Knight.

Part Features

Use 2mm Uniform Wall Thickness

Reference: Plastic Part Design for Injection Molding. Robert A. Malloy.

Uniform Wall Thickness, con’t


Gusset Bosses & Avoid Shrink Marks


Draft Overview

Reference: http://www.diecastingdesign.org/design/basic/draft/

http://www.diecastingdesign.org/design/basic/draft/

Use at 0.5 - 1.0 Degree Draft Angle (depends on texture)

Avoid Penetrations and Weld Lines

???


Avoid Undercuts if Possible


Avoid Undercuts if Possible

Lifter (Undercut)


Screw Bosses

No Flatheads!


Use Shut-Offs Instead of Slides


Use Shut-Offs con’t


Integrate Joint into Parts


Living Hinge

Hide Rib Shrink Marks


Materials

Materials

•Thermoplastic polymers (95%). Can go through molding cycle many times (i.e. similar to ice). No chemical bonds between strands.

•Thermosets (5%). Chemical react during process to form cross linked polymer chains. Irreversible. Excellent creep, dimensional stability, temperate and chemical resistance. Ex: phenolics and epoxies.

Materials, con’t

•Additives - Enhance a specific property (UV, stiffness, color,

flame retardants, etc). All have side effects. - Add chopped fiber (up to 30% volume). Strength

and stiffness, lose on impact, abrasion and tool live (cut down to 1/3). Properties approaching metal.

•Need to operate below 250C (400C max) •Low specific gravity (0.8 - 1.8) Steel = 7. Strength to weight ratio good. Automotive. •Some materials are transparent. •Very sensitive to changes in temperature (vs steel) •Good electrical insulation

Example: Chi Mei Polylac PA-747

http://www.matweb.com/


Resin Comparison

Resin Use Yield (MN/m2)

Modulus (MN/m2)

Heat Deflect (1.8 MPa : C)

Cost ($/kg)

Shrink (cm/cm)

ABS Housings 39 1,800 86 $2.09 0.004

PC Lenses 65 2,400 128 $2.81 0.007

POM Gears 65 2,800 105 $1.48 0.02

Polyamide Strength 123 2,750 65 $3.63 0.013

PP Food 36 1,380 93* $1.76 0.015

Aluminum 276 68,900 $1.75

Steel 435 205,000 $0.39

http://www.matweb.com/ http://www.nhh.com.hk/eng/trading/price_trend.asp


http://www.nhh.com.hk/eng/trading/price_trend.asp

Techniques

Use Moldflow Simulation

Use a clear shot to see mechanism (ABS -> PC)

Other Techniques

• Steel Safe Design

• Add additional ribs after first shots

• Use Inserts around change areas

• Review mold drawings carefully. Watch out for cooling lines.

Other Types of Molding

• Co-Injection / Overmolding (toothbrush)

• Gas Assist

• Low pressure (EE)

Calc Molding Size

• Assume holding 2 - 5 tons / sq. in

• Assume 50% cavity pressure lost due to friction

• Calc surface area of combined parts and runners

• Look up injection molding pressure (ABS = 1k bar)

• Calculate cavity pressure (Molding Pressure * 0.5)

• Calculate Tonnage: F = P * A

Shot Nomenclature

Shot

Shot Nomenclature

Shot Nomenclature


Shot Nomenclature, con’t

Tooling Fabrication

Tool Shop

EDM

Open Tools

Polishing

Finished Tools

Questions?

Technology

DFM Overview & Injection Molding - MIT - October 7, 2014